직업과 나

이상진 한국사법행정학회 1960 사법행정 Vol.1 No.3

Synthesis and characterization of strontium titanate powder via a simple polymer solution route

이상진,Pradheep Thiyagarajan,이만종 한양대학교 세라믹연구소 2008 Journal of Ceramic Processing Research Vol.9 No.4

A simple chemical route has been used to synthesize highly sinterable strontium titanate (SrTiO3) powders using titanium isopropoxide, strontium nitrate and ethylene glycol. This method utilizes complexation-polymerization using ethylene glycol as an organic carrier, which leads to compositional homogeneity and fine particle sizes. The calcined SrTiO3 powder showing a porous nature was fully crystallized to a cubic phase at 1,300 oC for 1 hour. Through ball-milling the porous SrTiO3 powders with particle sizes of 200-300 nm were easily obtained, which was sintered to a bulk density of 4.8 g/cm3 at 1,400 oC for 1 h with a grain size of approximately 6.0 mm. The relative dielectric constant and loss tangent of SrTiO3 sintered at 1,400 oC for 1 hour were 2078 and 0.022, respectively.

Fabrication of Nano-Sized β-TCP Powder by an Organic-Inorganic Solution Route

이상진,고신일,Myung-Hyun Lee,Nam-Sik Oh 한양대학교 세라믹연구소 2007 Journal of Ceramic Processing Research Vol.8 No.4

Highly sinterable, nano-sized β-tricalcium phosphate (TCP) powder was fabricated by an organic-inorganic solution route. Calcium nitrate and phosphoric acid were dissolved in D.I. water and 5 wt% polyvinyl alcohol (PVA) solution was added. The PVA was used as an organic carrier for the precursor gel. The dried precursor gel was fully crystallized to β-TCP at 1000 oC in an air atmosphere. As well, in the calcination process, the NOx and CO2 gases from the calcium nitrate and PVA polymer made the precursor gel to a soft and porous powder. The synthesized β-TCP powder was agglomerated showing nano-sized primary particles. The ball-milled and compacted β-TCP powder was fully densified at 1200 oC for 1 h. In particular, the sintered β-TCP showed pure β phase without phase transformation to α. In this process, the Ca/P ratio for stoichiometric β- TCP was adjusted by the control of phosphoric acid content. Highly sinterable, nano-sized β-tricalcium phosphate (TCP) powder was fabricated by an organic-inorganic solution route. Calcium nitrate and phosphoric acid were dissolved in D.I. water and 5 wt% polyvinyl alcohol (PVA) solution was added. The PVA was used as an organic carrier for the precursor gel. The dried precursor gel was fully crystallized to β-TCP at 1000 oC in an air atmosphere. As well, in the calcination process, the NOx and CO2 gases from the calcium nitrate and PVA polymer made the precursor gel to a soft and porous powder. The synthesized β-TCP powder was agglomerated showing nano-sized primary particles. The ball-milled and compacted β-TCP powder was fully densified at 1200 oC for 1 h. In particular, the sintered β-TCP showed pure β phase without phase transformation to α. In this process, the Ca/P ratio for stoichiometric β- TCP was adjusted by the control of phosphoric acid content.

Discussion on Social Aspects of Sustainability of Community: Focusing on the Naturally Formed Communities and the Boundary with New Development

이상진 대한건축학회지회연합회 2012 대한건축학회연합논문집 Vol.14 No.3

Sustainability has become one of the most important issues to dominate all other agenda in modern society. Most agenda regarding sustainability tends to focus on ecological or environmental sustainability. However, careful review of people's collective responses reveals that social aspects are more critical in determining sustainability of a city. Ecological sustainability, which mainly focusing on energy issues, can not be achieved in a city where social integrity is poor. For people to live in a city, social issues in a community may dominate all other issues since a community's allurement mainly comes from sociological attractions, such as good neighborhood. Thus, social integrity can be as much important as ecological issues to determine sustainability at least in a city. This paper aims to discuss the factors which affect social sustainability. Borrowing principles from nature to evaluate sustainability, two groups of factors are discussed for social aspects of sustainabilty; one group is connectivity/territoriality, the other is diversity/social contacts. Once precedent theories are reviewed to frame the discussion, two communities are selected to test the frame for analysis. Findings from the study reveal that two groups of factors, connectivity/territoriality and diversity/social contacts, are distinguishedly appeared from both communities.

Free Vibration Analysis of Elastic Bars using Isogeometric Approach

이상진,박경섭 대한건축학회 2011 Architectural research Vol.13 No.3

A study on the free vibration analysis of elastic bar is described in this paper. In order to determine the natural frequencies of bars, a bar element is developed by using isogeometric formulation. The B-spline is introduced to represent the geometry of bar and the same geometric definition is also used to define its unknown displacement field in isogeometric formulation. Therefore, the stiffness and mass matrices are derived by the order-free B-spline basis function. The efficiency and accuracy of the present isogeometric bar element is demonstrated by using several numerical tests. From numerical results, it is found to be that the present isogeometric element produces very accurate natural frequencies of bars. Finally, the present isogeometric solutions are provided as future reference solutions.

Isogeometric Analysis of Laminated Plates under Free Vibration

이상진 대한건축학회 2014 Architectural research Vol.16 No.3

A plate element is developed by using isogeometric approach in order to determine natural frequencies of laminated composite plates. Reissner-Mindlin (RM) assumptions is adopted to consider the shear deformation and rotatory inertia effect. All terms required in isogeometric element formulation are consistently derived by using Non-uniform rational B-spline surface (NURBS) definition. Gauss quadrature rule is used to form the element stiffness matrix and separately Lobatto quadrature rule is used to calculate element mass matrix. The capability of the present plate element is demonstrated by using numerical examples. From numerical tests, the present isogeometric element produces reliable numerical results for both thin and thick plate situations.

Characteristics of calcium phosphate powders synthesized from cuttlefish bone and phosphoric acid

이상진,이용천,윤영수 한양대학교 세라믹연구소 2007 Journal of Ceramic Processing Research Vol.8 No.6

Fine calcium phosphate powders were fabricated by using recycled cuttlefish bone. A raw cuttlefish bone easily turned to CaO by a calcining process and the calcined cuttlefish bone was mixed with phosphoric acid by a wet, ball-milling method. The crystalline phases of the heated mixtures were dependent on the mixing ratio (wt%) of the calcined cuttlefish bone to phosphoric acid. In a wide mixing ratio range of 1:1.1-1:1.7 wt%, calcium phosphates were synthesized and fully crystallized HAp and β-TCP were observed at about 900°C and above. The synthesized powders showed fine particles of below 0.5 μm in size. In this study, the crystalline development and Ca/P molar ratios of the synthesized calcium phosphate powders were studied by X-ray diffractometry and chemical analysis using ICP AES. In addition, the microstructures of the cuttlefish bone and synthesized calcium phosphate powders were examined by scanning electron microscopy.

A Form-finding Technique for Three-dimensional Spatial Structures

이상진 대한건축학회 2013 Architectural research Vol.15 No.4

A form-finding technique is proposed for three-dimensional spatial structures. Two-step discrete finite element (FE) mesh generator based on computer aided geometric design (CAGD) is introduced and used to control the shape of three-dimensional spatial structures. Mathematical programming technique is adopted to search new forms (or shapes) of spatial structures. For this purpose, the strain energy is introduced as the objective function to be minimized and the initial volume (or the initial weight) is considered as constraint function. Numerical examples are carried out to test the capability of the proposed form-finding techniques and provided as benchmark tests.

남북 군사력 우열에 대한 군간부들의 인식 평가

이상진 한국조사연구학회 2006 조사연구 Vol.7 No.1

This paper analyzes which of the military sub-fields has an effect on a soldier’s evaluation of South and North Korean military power. There are three objectives of this paper. First, it is to analyze whether the South is superior to the North in the overall military power and military sub-fields, without the presence of the US armed forces in South Korea. Second, it is to assess which of the military sub-fields influences the overall evaluation of military power through a regression analysis. Finally, it is to look at whether the professional soldiers have a motivational bias, due to an argument that the military personnel tend to exaggerate the inferiority of their own military power to get more budget for defense construction. Research in 2002 and 2003 tell us that South Korean military power is slightly inferior to North Korea's. However, research in 2005 shows that military power of South and North Korea is almost equal. The sub-fields in which South Korea is superior are in the order of War Sustainability, Information Warfare, Air Force, and Navy. North Korea is regarded to be superior in the fields of Atomic Biological Chemical Warfare Capability, Special Force, Reserve Mobilization, and Army. The higher ranked soldiers tend to evaluate that the North is superior to the South. 이 연구는 남북한 군사력의 우열을 비교함에 있어 군간부의 인식에 영향을 미치는 세부 전력분야가 무엇인지 설문을 통해 분석한다. 구체적으로 첫째, 주한미군을 제외한 남북한 전체 군사력과 세부 전력분야(육군, 해군, 공군, 특수전, 생화학전, 예비군동원, 정신전력, 정보전 수행능력)에서 군․계급별로 우열 차이를 분석하였다. 둘째, 전체 군사력 인식에 있어 어떠한 세부 전력분야가 영향을 미치는지를 회귀분석을 통해 평가하였다. 셋째, 남북 군사력 평가에서 발생할 수 있는 평가오류를 분석하였다. 2002년과 2003년 연구결과는 주한미군을 제외하면 한국군이 북한군에 비해 열세라는 평가이나 2005년 조사에는 비슷한 것으로 인식하고 있다. 세부 분야 중에서 한국의 우세는 전쟁지속능력, 정보전, 공군전력, 해군전력의 순이며, 북한의 우세는 생화학전, 특수전, 예비군 동원전력, 육군전력, 정신전력의 순이었다. 남북 군사력 우열 격차에 영향을 미치는 세부 전력분야는 육군, 해군, 공군전력, 특수전 전력 순이었다. 모든 전력분야에 있어 계급이 높을수록 한국이 북한보다 더 열세하다고 평가하고 있다.

국방운영에 있어 조정과 통합의 과제

이상진 한국국방연구원 2008 국방정책연구 Vol.24 No.3

This study focuses on the coordination and integration issue as one of key problems in the ROK MND’s defense operation. The issue of coordination and integration is caused by (1) lack of linkages between acquisition and operation & maintenance function and organization and (2) lack of working of the defense analysis & evaluation system in the defense PPBEES system. The MND and each service need to have capabilities and concerns to link a depth gap between the acquisition and the O&S function. It is necessary for the MND to coordinate various defense analysis organizations and some validity verification studies to review the necessity of the defense force improvement project’s requirement.